It is common for baking ovens to have a number of individual chambers or decks, mounted usually one above the other. This design permits several different products to be baked at once. In this arrangement, each product is located on a separate deck, having its own air temperature, steam atmosphere and bake time.
Separating one baking chamber from another is usually accomplished by inserting insulation (e.g. rockwool) between the baking chamber's floor and roof. This avoids unwanted heat from one baking chamber, travelling through to the walls which separate the adjacent baking chambers. The heating chambers are generally fully sealed from one another so that steam and byproducts of the baking process cannot travel into the insulating material, or into the other baking chambers.
While the insertion of thermal insulation material between the heating chambers has been effective in thermally isolating each heating chamber, the required thickness of the insulation layer has limited the number of vertically stacked baking chambers which can be readily accessed by the oven's operators. For example, the height of five baking chamber oven, using conventionally insulating material, is such that the top and/or bottom baking chambers are difficult to reach. The resulting poor ergonomics of these ovens represent a serious health and safety concern.
Excessive insulation thickness is especially a problem in ovens which have the heating elements located under the oven floor, forming a false floor and/or false roof. The heat built up under the false floor/roof creates a greater insulating need and hence thicker insulating material is required.
To address this problem, the use of highly compressed insulating material has only been partly successful. The pitfall with using compressed insulating material is that it can become brittle, and the denseness of the material can cause the material to gradually absorb heat, until it becomes as hot as the heating chambers above and below. This banking of heat then works in reverse to being an insulator, and instead acts as a heat source for heat into the chambers. The baking characteristics therefore changing as the heat bank gets hotter, leading to the production of poor quality baked goods. Further, insulating material although initially isolated from the baking chambers is still prone to entering the baking chambers as the oven deteriorates with age. Thus, the use of fibrous insulating material presents a hygiene and contamination hazard over the life of the oven which must be addressed.
Accordingly, there is a need for an improved insulation system which avoids the use of bulky and/or contaminating insulation material.